25B6; adjective GRUELLING, arduous, strenuous, onerous, punishing, crushing, demanding, exacting, taxing, exhausting, draining; informal killing; Brit. informal knackering; archaic toilsome.
easy.
BACK-BREAKING
Meaning of BACK-BREAKING in English
Concise Oxford thesaurus English vocabulary. Краткий оксфордский словарь английского языка тезаурус. 2012